A circuit board can include an array of various electrical devices. Typically, such devices include a connector that permits the circuit board to be electrically connected to auxiliary components. The connector has a circuit board interface with contacts that electrically connect with plated through-holes in the circuit board. The connector also includes a mate interface with contacts to connect to a mating connector of the auxiliary components. A conformal coating can be applied to protect the circuit board and connector from moisture and other substances. Such coatings can be deposited by a vapor deposition process. A cap can be provided on the mating interface of the connector to limit infiltration of the vapor during the deposition process. The cap is then later removed for connection to the auxiliary component.